This application is based on application No. 2002-023198 filed in Japan, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an image processing technique of a digital camera or the like for capturing an image of a subject by using a CCD image capturing device or the like.
2. Description of the Background Art
In recent years, in order to improve the picture quality of a captured image, the number of pixels of an image capturing part such as a CCD image capturing device is being remarkably increased in a digital camera. Meanwhile, reduction in size of a digital camera as a whole, and the like is demanded so that it is difficult for a display part for displaying an image to have the number of display pixels equivalent to the number of pixels of an image capturing part. The larger the number of display pixels becomes, the slower a processing speed gets, resulting in difficulty in displaying a line view smoothly. Consequently, it is not realistic to perform a displaying process by using all of the number of pixels of the image capturing part.
Therefore, a digital camera is generally provided with the display part having the number of display pixels which is relatively small and, at the time of live view display, a process of thinning pixels of an image obtained from the image capturing part is performed and a resultant image is displayed.
In such a manner, all of pixels which are captured by the image capturing part are not displayed at the time of line view display, so that a problem arises that it is difficult to recognize a focus state by a display image.
In order to solve the problem, Japanese Patent Application Laid-Open No. 2001-86385 discloses a technique of displaying an image subjected to a peaking process (process of emphasizing high frequency components of an image more than low frequency components) when an image enters an almost in-focus state so that an in-focus state can be easily recognized by using a displayed image.
However, there is a problem such that, only by performing a peaking process when an image enters an almost in-focus state as in the technique disclosed in the publication, when the image is out-of-focus, it is difficult for the user to visually recognize that the image is blurred by defocus only by viewing a displayed image. Conventionally, in some cases, although an image is actually out-of-focus, the user who views the displayed image is not aware of the blur by defocus and operates the shutter start button to start an image-capturing operation.
Even in a state where the subject is slightly out of focus, there is the possibility that the contour is emphasized by a peaking process. Consequently, the user feels as if the image is in focus. A problem arises such that it is difficult to accurately determine a focus state only by visually recognizing a displayed image.
The present invention has been achieved in consideration of the problems and its object is to provide a technique capable of making the user easily recognize an in-focus state by a displayed image.
The present invention is directed to a digital camera.
According to an aspect of the present invention, the digital camera includes: an image capturing device for capturing an image; an evaluating part for evaluating a focus state of an image obtained by the image capturing device; an image processor, when the evaluating part determines that the image is out of focus, for performing an image quality degrading process for emphasizing the out-of-focus state on the image obtained from the image capturing device; and a display for displaying the image subjected to the image quality degrading process in the image processor when the evaluating part determines that the image is out of focus.
According to the aspect, when a focus state of an image obtained by the image capturing device is evaluated and it is determined that the image is out of focus, the image quality degrading process for emphasizing the out-of-focus state is performed on the image obtained from the image capturing device, and the image subjected to the image quality degrading process is displayed. Thus, the user sees the displayed image and can easily recognize that the image is out of focus. That is, when the image is out of focus, the image of low quality is displayed, so that the focus state can be easily recognized. As a result, when an image is out of focus, the user can be prevented from erroneously giving an image capturing instruction, so that failures in image capturing by the digital camera can be reduced.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.